Visitor Lodge Plan
While the plan is meant as a reference during construction, I also help that it will give visitors coming to help an idea of what we are doing, how we're doing it, and what they'll be helping with. Some areas of this plan are overly detailed and some need more, but I believe all of the serious questions have been answered. I have left out almost all of the interior work that will be done mainly throughout the winter months.
The plan was created from a variety of techniques presented in several books and numerous web pages. I am including images and graphics from these books as well as others found around the web. If the authors of these books wish me to remove these images I will, however I felt it was extremely useful to have illustrations.
The time frames I have for each step are just a rough guide and I've tried to add significantly more time to each step than I hope it will take. I've also left a buffer of a month and a half before it starts to really get cold if we need it. The dates will certainly be changing as we go, so if you're curious about what we'll be doing during your visit, write us or call a couple weeks before you come.
The main books I used were :
- More Straw Bale Building - Magwood, Mack, and Therrien
- The Straw Bale House - Steen, Steen, and Bainbridge
- The Hand-Sculpted House - Evans, Smith, and Smiley
Dimensions
Outside Dimensions
228 x 288 = 649.77 sq. ft. footprint
Interior Dimensions
194 x 254 = 489.77 sq. ft.
Basic Description
The building will be a one-story rectangular load-bearing straw bale structure. The foundation will be a rubble trench foundation with an urbanite stem wall. The straw bales will be stacked on the stem wall and load-bearing door and window frames will be placed into the walls. A roof plate will then be placed on top of the bales and attached to the stem wall to compress and hold the bales in place. A ridge beam and rafter roof will be built on to roof plate and a metal roof will be attached to that. The gable ends will be filled in with regular and custom-shaped bales as well as cob to fill any small gaps. An earthen floor will be laid inside the house and the walls will be coated in an earthen clay plaster.
The building will be extremely well-insulated, the walls will have an estimated R-value of 45 and the cellulose insulated roof will have an R-value of 42. All of the windows will have 2 panes of glass, and a super-efficient wood-burning rocket stove will be used to heat the structure. The earthen floor will mitigate temperature swings with its large mass and carefully placed windows and eaves will only allow in winter sunlight.
The purpose of the building is to serve as a common area for visitors to the Ecovillage who are camping. The layout will include a large kitchen space, 2 bathrooms with showers, a storage space, and a large room for dining and general use. The building will also serve as our home until we build our personal place in the Ecovillage proper.
Other important aspects to the building are that a rainwater system will be set up to collect rainwater in a cistern from the metal roof. A solar hot water system will also be incorporated as well as a solar energy system. The building will also be designed with the intention of adding a large screened-in porch on the north side in the future which will assist in cooling the building during the summers.
There is currently no building code in Callaway County which frees us from those restrictions. The structure will still be built with safety and strength in mind. Construction will begin in May and hopefully completed in October. Overall expenses have yet to be calculated but we're looking at roughly $10-15,000, possibly significantly more or less.
Materials
We will be looking for these materials throughout the building process.
We will need to begin looking for a local farmer to supply us with straw bales sized to our specs after the grain harvest. The local farm supply co-op will be a good place to begin. There will be 32 bales per course and 8 courses minus bales for windows and doors and adding the additional bales for the gable ends comes to approximately 235 straw bales.
Bale Specifications
- 36 x 18 x 14
- Should be baled on the tight side and when lifted by the strings should not separate more than 5-6.
- The bales must also be dry and show no signs of mold.
As we will be trying to reduce our impact, we will try to use reclaimed lumber. If we can not find enough suitable reclaimed wood then we will try to have lumber from the land milled locally. If this turns out to be impossible or unfeasible for some reasons we will buy FSC sustainably harvested lumber.
Step 1: Site Orientation
The structure will be oriented to take advantage of passive solar design elements. The long side of the building will run along an east-west axis. In order to find true south with a magnetic compass the magnetic declination will need to need to be taken into account. The magnetic declination for Fulton, MO is 3 degrees East. This means that whatever the magnetic compass says is south, true south is actually 3 degrees west.
We will stake out the outer and inner walls at this point and make sure we are happy with the solar access, location of doors and windows, and ability to build on the porch later. Some of the floor plan and other steps may be changed after this step.
|
Tools & Materials
|
Schedule May 1 - May 3 |
Step 2: Site Preparation
First we will establish a protected area for tools and building materials. This will be a simple tarp attached to trees and possibly some temporary posts. We will place pallets on the ground to keep tools and materials off of the ground to avoid water damage.
There will be several 55-gallon drums of water for cleaning tools and other uses. There will also be a small wooden box filled with oiled sand for dipping tools in after washing for protection for rust. We will use recycled motor oil from an oil change.
The site will need to be cleared of brush, several short cedar posts and cement blocks from a previous structure as well.
|
Tools & Materials
|
Schedule May 4 - May 9 |
Step 3: Excavating the Foundation
To dig the foundation to the right depths stakes will need to be marked and a water level used to assure align the marks correctly. The rubble trench part of the foundation will be directly underneath the walls and will extend several inches below the frost line. The frost line in the area is safely 3. I have read that in Columbia the frost hasnt reached below 20 in the last 65 years. I think we will aim for 24" at the shallowest section.
The shallowest part of the rubble trench foundation will be 2 inches plus the frost line depth. The sides will slope slowly away from that corner at a rate of ½ every 4. The lowest corner of the trench will extend out to drain away any water which gets into the trench. The interior of the building will have the top soil removed and then be leveled and compacted with a tamper made from a tree small tree trunk roughly 3 in diameter. It may be sloped slightly so that any moisture will run off into the rubble trench. The trench will also be compacted with a tamper.
After pounding the datum stakes the next step is to remove the top soil from the entire building area inside of the stakes marking the outer edge of the wall. We will likely be using a grub hoe and shovels for this. The top soil will be loaded into a wheel barrow and deposited on the garden beds.
The rubble trench which will be 18 wide, will continue to be excavated. The subsoil will be placed on a tarp and protected from the weather so it can be used later. Rocks can also be set aside for later use. The tools used for this will be a pick mattock, shovel, and square spade and possibly a long-bladed trenching spade if the soil is not too compacted.
The different heights for each corner of the trench will have been staked and the water level will be used to insure that the slope is correct. The bottom of the trench and the sub floor will then be tamped with a home-made tamper with no more than a 3 diameter base and then level checked again.
|
Tools & Materials
|
Schedule May 10 - May 24 |
Step 4: Filling Rubble Trench
Two small trenches will be dug perpendicular to the rubble trench on the downhill side of the foundation. One will house a 3 diameter drain pipe that will be used to run an inlet water pipe from the cistern eventually as well as house electrical wires if the need be. The other small trench will be for a 2 diameter PVC drain pipe that will run alongside the rubble trench drain pipe. The 2 drain PVC drain pipe (pipe size calculator) can handle over 20 gallons a minute of waste water (more than the maximum of all the planned faucets being used at once). This trench will line up with the sinks later on. Both the inlet and outlet pipes will plugged.
2 thick polystyrene rigid foam insulation will be placed against the outside section of the rubble trench for insulation. A 4 polyethylene leach bed pipe will be laid in the trench to facilitate drainage. The section of drain pipe leading out of the rubble trench downhill will not be perforated to keep this section clear of debris as it will not be protected by a roof overhang and silt may build up in it.
The indoor drain pipe may connect directly to the foundation drain pipe which will eventually empty into an on-level swale to slowly absorb into the ground or overflow over a wide area to reduce erosion. There will be no black water draining as we will be using composting toilets.
Once the 2 utility pipes and the foundation drain pipe are in place the rubble trench will begin to be filled with 1-3 diameter rocks as well as broken bricks and larger rocks removed during the excavation. The rubble will be compacted with a wide-based tamper every 6, then 1 below grade a layer of used polypropylene feed sacks will be laid down to slow the amount of dirt and silt into the drain pipe. Another 6 layer of rocks will then be tamped down so that the final level of rocks in the trench is 6 below grade.
|
Tools & Materials
|
Schedule May 25 - May 29 |
Note
John Klick(johnk@ktis.net) $30/truck load 2-3 diameter gravel
Step 5: Urbanite Stem Wall
A stem wall will be constructed using reclaimed concrete that does not contain rebar, this is also known as urbanite. Urbanite is often available for free or very cheaply from excavation contractors and is usually broken-up sidewalk or old floor slabs.
The urbanite pieces will be mortared together with a mixture of lime, cement, and sand. Normally we would prefer a simple lime/sand mix to exclude cement altogether, but because lime/sand mortar takes 2 weeks to cure as compared to a single day using cement and we are under time constraints with this building we will make an exception.
The wall will extend 1 above grade and 6 below bringing the total height of the stem wall to 16. Every 3 starting 2 from the end of a wall, and being aware of doors and windows, a section of PEX water tubing will be run under the second course with the ends exiting at the top of the stem wall within 1 of each side. Eventually metal wires will be run through these tubes and over the roof plate in order to precompress the straw bales and then covered with the plaster coat.
Also spaces will be left for the 2 doors each space will be the width of 1 bale or 36. The gap only needs to be 4 lower than the rest of the stem wall as the interior floor level will be 8 above grade to match that height. The gap should act as a step and more attention may be given to placing a smoother piece of urbanite as the top course in the gaps. The location of the gaps is shown in the floor plan. Anchor bolts should be embedded on the sides of the gap and protrude 1.5 to secure the door bucks.
The mortar will be mixed at a ratio of 1 part lime/2 parts cement/9 parts sand. My estimate on the amount needed is just a guess. It could easily be double or more. Because the urbanite will likely be of even thickness each course will be leveled. The mortar should take a day to harden and should be protected from the sun with a tarp.
|
Tools & Materials
|
Schedule May 30 - June 14 |
Step 6: Bale Curb
On top of the urbanite stem wall 2x3 or 2x4s will be laid parallel spaced so that the outside edge of the boards will line up with the sides of the straw bales which will placed on top of them. In between the boards packing peanuts will be placed as insulation. The bale curb prevent moisture from wicking into the bales and also serve as a place to attach flashing to direct water away from the bales. Additionally wiring can be run through the curb if it ever becomes necessary.
The curbs will be attached to the foundation with the use of concrete screws and the space between them filled with salvaged packing peanuts as insulation. The approximate length of the lumber needed is 194.
|
Tools & Materials
|
Schedule June 15 - June 18 |
Step 7: Door & Window Bucks
Bucks are wooden frames which are built into the walls to make a hole in the wall for windows and doors to later be attached to. They need to transfer the load of the bales and roof plate above them to the bales beneath them in the case of windows or directly to the foundation in the case of door bucks. The wider the buck the more structurally stout it needs to be to transfer the load, thus thinner taller windows need only simple bucks using less lumber and also have the added benefit of allowing light deeper into the structure. The bucks height will match that of compressed bales which is typically 3%.
There will be a total of 6 window bucks. 5 of them will be tall and thin and 1 above the sink will be wider and shorter. Their dimensions and lumber requirements after compression calculation is as follows:
Tall & Thin Window Buck(3)
- 16 x 4 6.33
- 10.9 of 2x8
- 10.9 of 2x10
Square Window Buck(3)
- 3 x 23
- 8 of 2x8
- 8 of 2x10
Door Buck(2)
- 36 x 85.5
- 19.75 of 2x8
- 19.75 of 2x10
The 2x8s and 2x10s will be connected together with a metal connector plate to essential form a 2x18(the width of the wall).
The door buck can be installed as soon as the stem wall is dry. Holes should be drilled to allow the anchor bolts to be sunk into the wood and not protrude into the doorway. Temporary cross braces should be installed so that the bucks remain square during the wall raising.
|
Tools & Materials
|
Schedule June 19 - June 24 |
Step 8: Roof Plate Construction
The roof plate will be made of 2x4 lumber in a ladder shape. The 2x4s will be so that they are 3.5 tall. The two rails of the plate will be spaced 18 the same as the width of the stem wall so that the edges will protrude 1 on either side of the bales to provide a plaster stop. Cross ties will be placed between the rails every 16 and every other cross tie will correspond with the tubing in the stem wall.
The cross tie 2x4s that are aligned with the tubing will be ripped to make it a 2x3 and attached so that there is a 1 gap at the top of the roof plate. Holes will be drilled in the rails so that they are directly above this 2x3 cross tie. This will allow the precompression wires to run through the roof plate along a cross tie and back down the other side of the wall.
The 2x4s that make up the rails will be staggered so that the end of one 2x4 does not occur across from the end of another 2x4 so as to avoid a weak spot. The rails will have additional 2x4s nailed inside of them to double there width over window and door bucks extending 1 beyond the width of the buck on both sides.
The roof plate will eventually be sandwiched between plywood with the gaps in between the cross ties filled with packing peanuts for insulation. However, the packing peanuts and top cover of plywood will not be installed until the roof plate has been secured on top of the bale walls. The roof plate will also be left in sections so that it can be lifted on to the bale wall more easily. The sections will be carefully labeled with their positions.
Tools & Materials
|
Schedule June 25 - June 30 |
Step 9: Raising the Walls
The straw bales will now be stacked on the bale curbs with each courses joints overlapped by a solid bale for structural integrity. Pieces of plywood will be hammered together to form right angles and used as guides for the corners to keep them plumb. Also, a number of half-bales will be needed, this involves using bale wire and a bale needle to re-tie each half of a bale and then cut the original bale wires at which point the two half-bales can be separated.
The bales will also be dipped in clay slip on the two sides which will be the interior and exterior sides of the wall. Dipping the bales in clay slip, a blend of clay and water, has many advantages. It removes the need for adding the often difficult first clay slip coat before plastering, reduces the amount of settling for load-bearing buildings, are easier to stack, eliminate the labor-intensive trimming of the bales, and makes it much easier to apply the plaster coat.
Several bales in the 2nd course will be cut to make room for electrical outlets, 18 gauge wire will also begin to be run from those cuts, zig-zagging through each course until they will enter the roof plate and be run to a central breaker box in the storage area. The same will happen for several switch boxes in the 4th course but these cuts will be double wide for boxes with multiple switches. The 18 gauge wire will allow for roughly 1100 watts per circuit. The electrical system will be laid out in detail later. Exhaust fans may also be placed in the wall above the composting toilets, how and exactly where they would go is yet to be determined.
A large group of people may be able to raise the walls quickly but it would be wise to have everyone stacking to stop after each course to make sure that the cut bales are in the right places and the window bucks are placed correctly as well as braced and remaining plumb. A bale beater or something relatively heavy can be used to knock the bales down into place better.
Gaps in between bales will need to be stuffed with loose straw or flakes from a bale for larger gaps. Once the walls have been raised they should always be protected by tarps until the roof is in place.
|
Tools & Materials
|
Schedule July 1 - July 5 |
Step 10: Installing Roof Plate and Precompression
Thin plastic will be laid on top of the bales to prevent any water from dripping from the roof into the interior of the bale wall. The roof plate will be lifted on top of the wall and plastic and connected together using screws for a strong connection. Holes will be drilled in the bottom to allow the electrical wiring into the interior of the roof plate. More holes will be drilled in the cross ties to allow those wires to travel to the storage room.
The distance from diagonal corner to diagonal corner will be measured and pulled into square if its not already.
9-gauge fencing wire will be run through the PEX tubes in the foundation up and through the corresponding holes in the roof plate so that the ends of the wire meet on the outside of the wall. A small closed loop will be made out of the top end of the wire using a saddle clamp. The bottom end will be run up through this loop and pulled down.
A fence stretcher will be attached to the end of the bottom wire so that it tightens under a downward force. Another fence stretcher will be attached further down the bottom wire so that it tightens under and upward force. A come-along will be attached between the 2 fence stretchers so that when it is tightened they will tighten the entire length of wire and pull the roof plate down. The walls should be checked for straightness throughout this process and corrected with a sledge hammer.
Each wire will be tightened several times and after it is tightened the come-along and fence stretchers can be removed without tying off the wire since the bend through the loop is sufficient to hold it in place. The first round of precompression should compress the walls roughly .5 lower than the lowest height. The idea behind precompression is not to squish the bales as much as theyll go but to be sure that the walls wont settle any more after the plaster is applied.
Typically you want 1-3% compression, which on a bale wall of 7 courses of 14 tall bales would be 1-3 of compression. To make the plate even a measuring stick can be cut to the height of the wall minus 3 with a cross piece so that it can hang from the roof plate and when it touches the stem wall its at the correct height.
The final round of tightening should involve making sure the top plate is level with a spirit level. A sledge hammer may be needed to knock the roof plate back into square after checking the diagonals. The wires can then be either twisted or saddle clamped and additional wire trimmed off to get it out of the way of the plaster that will come later.
After the roof plate has been compressed and leveled it can be filled with packing peanuts and have the top cover of plywood screwed into place.
|
Tools & Materials
|
Schedule July 6 - July 10 |
Step 11: Wall Finishing
Even though the gaps were stuffed before the precompression the walls should be checked again and stuffed if necessary. The spaces can be stuffed with loose straw folded on itself or even with cob.
The walls should also have any further straightening done to them at this point. Sledge hammers and bale beaters will be used to accomplish this.
The electrical outlets can now be placed in the holes that have been left for them. To attach them to the wall they will be screwed to stakes made out of plywood and hammered in between the bales to hold them in place.
In the area which will be the storage closet, a piece of plywood 2 x 34 will have more plywood stakes screwed to it horizontally on the ends and the whole piece will be hammered in to the bales. This piece of plywood will eventually have a breaker box, inverter, and charge controller attached to it.
Flashing should be attached to the outside of the wall on the bale curbs so that water will be directed away from the bales and down into the rubble trench. It will need to have spaces cut to make space for the precompression wires.
|
Tools & Materials
|
Schedule July 11 - July 13 |
Step 12: Gables, Ridge Beam, Rafters, and Cross-Ties
The roof will have a pitch of 4 in 12 or rising 4 for ever 1 of run. This comes to a rough slope of 18.5 degrees.
The ridge beam will be made of 4 2x12x16 with 2 being bolted together offset by 2 in order to form essentially a 4x12x17(2) and then the ends being spliced together to form a 4x12x34 ridge beam. The rafters will be 2x12x16 and spaced 24 apart meaning that 14 will be needed for each side.
The gables will be formed with a pyramid of straw bales stacked 4 courses high directly on the roof plate secured by hammering nails sticking halfway out of the cross ties for better footing. Once both gable ends have been completed with the top course made only of 1 double-tied half bale centered in the mid-point of the side, the ridge beam can be lifted on top and placed so that it sits in the middle of each of these half-bales. A piece of plywood will be attached between the ridge beam and the bale to distribute the load. The idea is that some of the roof load will be directed down into the gable-end walls instead of all being directed into walls the rafters rest on as they do in normal ridge beam/rafter roofs.
The exact height of the top of the bale pyramid will be used to calculate the exact pitch of the roof, but it should come out be roughly 48 above the roof plate. With the exact angle of the roof, the position and notch will be cut out in the first rafter using the assumption that the bales will compress 1.5%. The notch or bird mouth will fit around the outside edge of the roof plate and be 4 deep, roughly matching the height of the roof plate. The rafters will then extend an additional 33.8 to create an overhang of 31.7.
The rafters will be attached to the ridge beam and roof plate with either L brackets or angled screws. Joists connecting the rafters from one side to the other may be necessary, but hopefully avoidable as we would like to use as little lumber as possible.
The purlins will be made of 2x4 lumber which will extend 4 beyond the last rafters so that they are even with the ends of the ridge beam. This will allow the roof to have a 3 overhang on ends. Because the top of the gable is higher than the ends of the rafters it needs a larger overhang to keep rain off of the bale walls. There will be at least 3 rows of purlins on each side.
|
Tools & Materials
|
Schedule July 14 - July 28 |
Step 13: Earthen Floor Base Layer
If there are enough tarps to lay over all of the rafters and essentially make a temporary roof then this will be the next step, otherwise this step will come after installing the metal roof.
First drain pipe will be laid To begin with the interior sub floor will be cleaned and then filled with 4 of Ύ-1.5 clean gravel. I estimate that it will take 9 tons of gravel to fill it to this level. The gravel will then be tamped down with a broad metal tamper. Using a spirit level attached to a straight 2x4 the gravel should be perfectly level.
The adobe mixture will be poured in the 3 different layers on top of this gravel. Each layer will be thinner and made of finer material than the one before it. The mix for each layer will be determined by several test pours to check for cracking. The base layer will be made up of 50-80% sand and gravel. The gravel should be 1.5 and below in diameter so that it can be sifted through a ½ or Ύ metal screen. The larger gravel will be used in the base layer and the smaller will be set aside and used in the following layers.
I estimate the adobe layers will require 6 tons of gravel and 2 tons of sand. The remaining 20-50% is clay or soil with a high clay content as well as lots of full-length straw straight from a bale. Once again, make sure to do tests on several variations on the mix to find the one that has least amount of cracking. If it cracks, reduce the amount of clay, if it is dry and crumbly, increase it.
Using 2 straight pieces of 2x4 for leveling board, set them on edge roughly 2 apart parallel to the wall farthest from the door. Level both boards along their length and relative to each other. Next, shovel the base layer mix in between the boards and use another piece of lumber to scrape the mix flat making sure to leave the surface rough so that it bonds well with the next layer. Remove the leveling board farthest from the door(the mix should be firm enough that it doesnt slump), then fill the gap with more mix after roughing the interior edges for a good bond. Place the removed leveling board 2 closer to the door on the other side of unmoved leveling board and repeat the process. Some surface voids are ok.
The PVC drain pipe will be extended 6 inward and then have an elbow attached so that it comes up out of the floor underneath the future location of the sinks. The pipe will the be buried in the base layer.
It may take a couple of days to weeks for this layer to dry. If there is only a tarp over the roof then this should be removed during clear weather to speed the drying process. Fans may also be necessary. While the base layer is drying the roof can be installed.
|
Tools & Materials
|
Schedule July 29 - August 2 (Pouring) |
|
Tools & Materials
|
Schedule August 3 - August 12 |
Step 15: Earthen Floor Second Layer
The second layer will be applied when the base layer is thoroughly dry. Check to make sure that the base layer is still level. The same 2x4s can be used but this time laid flat so that the layer is 1.5 thick instead of 3.5. If the base layer isnt perfectly level then sand can be sprinkled under the boards to make it level. The boards will be laid perpendicular to the way they were during the base layer so that none of the seams will overlap.
Before the new mix is laid down the base layer should be wetted for good adhesion. Remember to roughen the edges inside the gap that is left when a board is removed before pouring in more mix.
The mix for the second layer will be smoother than the first. It will use only gravel Ύ or smaller. If the base layer cracked it will use a higher percentage of sand, gravel, and fiber. Instead of full-length straw this time, chopped straw and/or fresh cow or horse manure can be used for finer fiber. Make sure to try test mixes of this on a 3 square on top of the test 3 square that had the mix used for the base layer.
|
Tools & Materials
|
Schedule August 13 - August 16 (Pouring) |
Step 16: Plastering Walls
Typically 3 coats of plaster are applied, but because the bales were dipped first, we will only have to apply 2 coats. The plaster we will likely be using, depending on the clay content of the subsoil extracted during the digging of the rubble trench, is earthen clay plaster. It can be applied by hand and smoothed with a trowel, is extremely cheap, and has very low embodied energy.
The mix for the 1st coat will be Ύ sand to Ό clay and an equal volume of chopped natural fibers such as chopped straw or cattail fluff. The excavated subsoil will be tested to see what percentage it is naturally. It is likely we will have to add sand to the mixture, which we should have some left from the building of the stem wall if get a whole truckload instead of just a half of one as is likely needed for the stem wall. The soil will be put through Ό screen before being used. Water should be added until it is the consistency of cake batter. Different ratios will be tested on the bales, too crumbly and there is too much sand, if it cracks, it has too much clay.
The exterior walls will be done first since they are more vital to the protection of the bales and to give the second earthen floor layer time to dry. The walls will be plastered so that they cure slowly and are not immediately in direct sunlight so the western wall will be plastered first, followed by the north wall at midday, the east wall in the afternoon and the south wall in the evening. If that cannot be accomplished then a tarp will be hung over the wall to protect it.
Before applying the plaster the edges of the windows and door buck will be taped over. Then tarps will be put down on the ground underneath the section of wall being plastered to stop the plaster from clogging up the rubble trench and generally making a mess. A backpack sprayer will be used to lightly mist the walls starting at the top. The plaster will be applied by hand beginning at the top of the walls and working down. After an area of 3-6 square feet has been roughly plastered by hand a trowel will be run over the area to smooth it out, followed by a stiff-bristled broom make horizontal scratches which will allow the 2nd coat to bond with the first. Pruning shears or wire cutters will be used to cut any pieces of straw sticking out of the bales.
The 2nd coat will be a finish coat and the ingredients will be screened so that it will be smoother. We will also be incorporating fresh cow manure as the fibers are very fine and it gives the plaster an oily and water-resistant coat. We may also add a small amount of linseed oil for more water resistance as well as some hydrogen peroxide to help prevent any mold growth. The clay and straw will be put through a 1/8 screen and the sand through a 1/16 window screen. This finish coat plaster will contain more sand and manure vs. clay than the base coat.
The 2nd coat will only be Ό thick or if more thickness is needed another coat of the finish plaster can be applied. The wall will be well misted ahead of the plaster to create a better bond and prevent the base coat from sucking the moisture out of the finish coat. After the coat has been applied the tape should removed from the door and window bucks so that it doesnt pull of chunks of plaster once it has hardened.
The process will be repeated for the interior walls as well. The plaster may take up to a month to fully cure at that point it may be necessary to fill in areas around door and window bucks where the plaster has pulled away due to shrinkage.
|
Tools & Materials
|
Schedule August 17 - August 21 (Exterior) |
Step 17: Roof Insulation
The roof rafters were intentionally extra wide to provide space for more cellulose insulation. Used potato sacks or other types of similar material will be attached with a staple gun to the underside of the rafters to provide the bottom sheathing and the insulation will be stuffed down between the rafters. The cellulose will not be shoved up into the air gap made by the purlins to allow condensation to escape up and out small vents at the gable ends above the insulation.
Cellulose insulation has an R-value of 3.5 per inch, and with roughly 12 in the rafters will provide an R-value of 42 for the ceiling. This matches up nicely with the wall R-value of 45.
The bags of cellulose cover 16 cubic ft. each, with a roof that will have about 840 cubic feet that needs insulating, means about 53 bags of insulation. Lowes offers free day rentals of the cellulose blower with a purchase of 25 bags or more, so we will buy 25 bags and do half the roof one day and buy the rest the next to get 2 free days with the blower.
|
Tools & Materials
|
Schedule August 26 - August 30 |
Step 18: Earthen Floor The Finish Layer
The finish layer will only be ½ Ύ thick. The mix will be extremely smooth and creamy like cake batter and not contain gravel. The clay soil will be put through an 1/8 screen. The sand will be sieved through a fine window screen. Cow manure will again be used but it will be soaked overnight and grated through a screen to break up lumps.
A different method for creating a level floor will be used this time. Nails will be hammered in to the desired depth and a level used to check for accuracy. The mix will be poured in and level with a pool float or other type of trowel to the height of the tops of the nails and the nails will be removed as it progresses. The second layer will need to be wetted for a good bond.
The floor should be allowed to completely dry before continuing. This may take several days or more. Fans will speed up the process.
Coat of boiled linseed oil will be applied when the floor is dry. The oil should be warmed if possible and can be spread using a rag, brush, roller or soft sponge and should applied until it begins to puddle and the excess should then be wiped off. Once that layer has dried a new layer of linseed oil will applied, but this time the oil will be diluted 25% with turpentine, citrus thinner, alcohol, or mineral spirits. It will then be allowed to dry and another layer, this time 50% oil and 50% thinner applied, and finally a layer of 25% oil and 75% thinner.
Once the final layer is dry the floor is essentially done, however a paste made of 1 part beeswax to 2 part linseed oil can be applied with a rag which will essentially water proof the floor. The coat will wear off with time and can be reapplied every year or so if necessary.
|
Tools & Materials
|
Schedule August 31 - September 8 |
Conclusion
After the floor finished drying we should be able to move in for the winter. We will continue to build the interior walls, bathrooms, showers, etc. We'll be setting up a small solar power system as well as installing a water system with solar heated hot water.
The Plan | The Land | Media | Calendar | Contact Us